The main objective of the proposed research is to measure and to correlate the integrated concentrations and production rate of various peptide and steroid hormones (HGH, insulin, glucagon, cortisol, 17-hydroxyprogesterone, etc.) in some physiological and pathological conditions. The integrated concentration of the hormone under consideration is measured in a pool of blood withdrawn at a constant rate utilizing a small portable pump connected to a heparinized catheter developed by the investigators. In addition, continuous monitoring of blood glucose is carried out by connecting the non-thrombogenic system to a glucose analyser. Efforts will be made to determine the clinical importance of these findings as far as diagnosis and treatment of conditions which in various ways can affect growth.